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 ###Instrução: Qual classe antes de 1990 tem pontos de 33?
 ###Tabelas: CREATE TABLE atomic_radii (atomic_radii_id AUTO_INCREMENT PRIMARY KEY, number INT, symbol VARCHAR, name VARCHAR, empirical † VARCHAR, Calculated VARCHAR, van der Waals VARCHAR, Covalent (single bond) VARCHAR, Covalent (triple bond) VARCHAR) CREATE TABLE provinces (provinces_id AUTO_INCREMENT PRIMARY KEY, Province VARCHAR, Inhabitants INT, established INT, President VARCHAR, Party VARCHAR, Election INT) CREATE TABLE grand_prix_career_statistics (grand_prix_career_statistics_id AUTO_INCREMENT PRIMARY KEY, Year INT, Class VARCHAR, Team VARCHAR, Machine VARCHAR, Points INT, Wins INT) CREATE TABLE group_i (group_i_id AUTO_INCREMENT PRIMARY KEY, Position INT, Club VARCHAR, Played INT, Points INT, Wins INT, Draws INT, Losses INT, Goals for INT, Goals against INT, Goal Difference INT) CREATE TABLE most_wickets_in_the_tournament (most_wickets_in_the_tournament_id AUTO_INCREMENT PRIMARY KEY, Player VARCHAR, Overs VARCHAR, Runs VARCHAR, Wkts VARCHAR, Mdns VARCHAR, Econ VARCHAR)  
SELECT Class FROM grand_prix_career_statistics WHERE Year < 1990 AND Points = 33